SOUTH BEND, Ind. — The Southern California-Notre Dame rivalry is different than most.

It doesn’t involve in-state opponents, such as Alabama and Auburn, or schools from neighboring states, such as Michigan and Ohio State, or even an adversary with a similar mission, such as Army and Navy. USC and Notre Dame are separated by nearly 2,000 miles and their homes couldn’t be more different.

What the two private schools have in common is a history of great teams and great players. No other rivalry game can claim the 22 national championships, with 11 apiece, or the 13 Heisman Trophy winners (14 if you count the one Reggie Bush won in 2005 that was later vacated).

The game has helped vault the teams to national championships and cost them titles as well. Lately, though, the game has not lived up to its reputation.

Since Notre Dame won three straight over USC by four points from 1989-91, the game has been known more for lopsided victories than exhilarating finishes. Only seven of the past 21 games have been decided by a touchdown or less, including a 17-17 tie in 1994. During that same span, USC won six times by 20 points or more while the Irish did it once. The Irish won three others by two touchdowns or more.

It’s not just the competitiveness that has been lacking. While at least one team has been ranked in 64 of the 75 meetings since The Associated Press started the poll in 1936, this season marks the third time in the past four years where neither has been ranked. The last time both teams were ranked was when the No. 3 Trojans beat sixth-ranked Notre Dame 44-24 in 2006.

Notre Dame coach Brian Kelly said last year it hadn’t been a great rivalry of late because the Irish hadn’t won enough. He said that’s changed now that the Irish have won two of the last three, with last season’s 22-13 victory sending the Irish to the BCS championship game. Kelly said he hopes moving ahead both teams will be competing for BCS bowl berths and playing “on equal footing.”

“I think both programs are looking forward to those days where it’s a great matchup year in and year out,” he said.

It’s been a while since that has been the case.

Here are five things to know as USC (4-2, 1-2 Pac-12) seeks its sixth straight win against the Irish (4-2) at Notre Dame Stadium:

PLAYING BOTH SIDES: The schools believe Notre Dame running back Amir Carlisle will become just the second player to compete on both sides of the rivalry Saturday. He was a kick returner as a freshman for the Trojans in 2011, although he never touched the ball, and transferred to Notre Dame after the season. The only player to previously play for both sides in the rivalry game was wide receiver Speedy Hart, who played for the Irish in the “Green Jersey” game in 1977 and for USC in 1980, playing for the winning side each time.

NOTRE DAME STADIUM: The last time Notre Dame beat USC in South Bend was 2001, a fact Kelly wasn’t aware of until asked about it Tuesday and USC interim coach Ed Orgeron doesn’t want his players thinking about that, saying “there’s been a lot put on this team.” The Trojans, he said, are focusing on the game being Game 2 of a new season after the firing of Lane Kiffin. Orgeron won his debut last week, 38-31 over Arizona, and he could join John Robinson and Paul Hackett as the only USC coaches to beat Notre Dame in their first season.

STRUGGLING DEFENSE: Four games into the season, USC’s defense led the nation in red zone defense, was second in tackles for loss, third in rushing defense and fourth in total defense. But in the past two games, opponents have scored 93 points, rushed for 406 yards, passed for 714 yards and have scored on nine of 10 trips inside the end zone, including six touchdowns. Orgeron said busted coverages and defensive backs letting receivers get behind them have been among the problems USC needs to fix.

GROUND GAME: Notre Dame tore out much of the turf following its game against Oklahoma on Sept. 28 and installed new grass. Kelly said he hasn’t seen the field, but has heard good reports. “We’re hopeful. We expect good results,” he said. “There is a bit of uncertainty when you don’t, obviously, know what to expect.”

COLD WEATHER: The National Weather Service predicts temperatures in the 40s Saturday evening. USC is 9-7-1 in cold weather games, which the school defines as temperatures cold enough to be mentioned in game stories. The Trojans are 1-5-1 against Notre Dame in such games. The last cold weather game USC played in South Bend was in 1959, a 16-6 Irish win. That was the last time the regular-season finale was played in South Bend.